I haven't seen much from everyone, especially Hiruzen, but I'm rereading the whole manga anyway. Right now, there are only a few names that pop in my mind, and I'll go with Itachi, Jiraiya, and Kakashi, the latter being the most balanced ninja in this series in my opinion (well, not until the Kamui hype in the latest chapters).
It is ether Kakashi, Jiraiya or Hiruzen.
-I feel like these 3 are above avg or a master in most jutsu(gen, nin and tai) areas. And are also quite fast, smart, high stamina and have powerful techs.
-I know Hiruzen is a maybe b/c we never saw his prime. But we know from Hype that he was skilled in many fields